In specific terms, that means the Hell-escapee of the week isn’t merely a diabolical fugitive to be apprehended and sent back to Hell, but a deliberate reflection of Detective Ezekiel Stone’s (Peter Horton) personality and situation.
This small moment reveals that even in a situation where Stone has been grievously wronged and feels absolute rage, he realizes he can still be decent to someone else who is hurting. There is nothing to gain by shattering Evelyn’s image of her wayward child. So instead of laying more hurt at her feet, Stone holds his words, and it’s a powerful and moral act. It’s a great moment for the episode, and for the series.
Stone knows too well that to indulge those feelings of denial, pride and self-righteousness with action (and murderous action to boot) is to indulge his dark side, especially since he abuses his position as a police officer.
He keeps finding shades of gray in the human experience, and trying to countenance what they mean. The show thus asks questions about the differences between vengeance and justice, and suggests that even “monsters” like Jax are loved by their mothers, and that such love can be respected.